Imidazole dyestuffs of the anthraquinone series



United States Patent 2,989,535 IMIDAZ'OLE DYESTUFFS OF THE ANTHRA-QUINONE SERIES Hermann Geeren, Ludwigshafen (Rhine), Friedrich Ebel,Mannheim-Feudenheim, and Willy Braun, Heidelberg, Germany, assignors toBadische Anilin- & Soda-Fabrik Aktiengesellschaft, Ludwigshafen (Rhine),Rhineland- Pfalz, Germany No Drawing. Filed Aug. '6, 1959, Ser. No.831,944 Claims priority, application Germany Aug. 8, 1958 7 Claims. (Cl.260-3093) This invention relates to new imidazole dyestuffs of theanthraquinone series and to a process for their production.

The imidazole dyestuffs of the anthraquinone series hitherto known fromthe literature have various defects, for example inadequate wet fastnessproperties and/or small color strength.

It has therefore been a problem to find and prepare new imidazoledyestuffs of the anthraquinone series which would not have these defectsand which at the same time would be characterized by the clarity andfastness to light of the known imidazole dyestuffs of the anthraquinoneseries.

This problem has been solved in accordance with the present invention bythe production of vat dyestuffs which correspond to the general formula:

wherein each of the two anthraquinone systems may contain in the 3- or4-position or in the 3'- or 4'-position halogen atoms, for examplechlorine or bromine atoms, or alkoxy groups, for example low molecularweight alkoxy groups, i.e. lower alkoxy groups such as methoxy or ethoxygroups, and A represents a phenylene radical which in turn may bear thesame halogen atoms or alkoxy groups.

New dyestuffs of special technical interest are those which have thegeneral formula:

We have now found according to this invention that the above valuablevat dyestuffs with very good wet fastness properties are obtained byreacting a 1,2-diaminoanthraquinone which may contain halogen atoms oralkoxy groups in the 3- or 4-position, with a compound of the generalformula X A-X in which X and X each represents a HOOC--, ROOC,

Y HC- or Y C-group, Y being a halogen atom and R a I simple alkyl,aralkyl or aryl radical, and A represents a phenylene radical which inturn may bear halogen atoms or alkoxy groups.

Examples of 1,2-diaminoanthraquinones which have halogen atoms or alkoxygroups in 3- or 4-position are 1,2 diamino 3 methoxyanthraquinone, 1,2diamino- 3-bromanthraquinone or -l,2-diamino-4-chloranthraquinone.Chlorine or bromine atoms are examples of halogen atoms. Lower alkoxygroups, such as methoxy or ethoxy groups, are preferred. ,Methyl, ethyl,benzyl or phenyl radicals are examples of simple alkyl, aralkyl orchlor-terephthalic acid, 2,5-dibromoterephthalic acid, 2,5-

dimethoxyterephthalic acid, isophthalic acid, 4,6-dichlorisophthalicacid, 4,6-dibromisophthalic acid; and the esters and acid halides ofbenezene dicarboxylic acids or benzene dialdehydes, as for exampleterephthalaldehyde, 2,5- dichlorterephthalaldehyde, 2,5dibromoterephthalaldehyde, isophthalaldehyde, trichlorisophthalaldehyde,

4,6-dichlorisophthalaldehyde,

octachlor para xylene, omega,omega,omega,omegatetrabrom meta xylene,omega hexachlor meta xylene,

benzene, 2,5 heptachlor-para-xylene.

The new vat dyestuffs are obtained in the known manner for theproduction of imidazoles as described in the literature, elg. bycondensation of one mol of a compound of the general formula X -A-- X inwhich A, X and X have the meanings given above, with 2 to 2.2 mols of1,Z-diaminoanthraquinones of the above-mentioned kind, preferably in asolvent and/or diluent. It is often helpful to include in the reactionan agent for binding water or acid, generally called acid-binding orwater-binding agents, It is possible to start either from v i one1,2-diaminoanthraquinone or from different 1,2-di aminoanthraquinoneswhich are condensed simultaneously "1 or successively with theabove-mentioned compounds of the above general formula X -A-X Examplesof solvents and/or diluents which are at the same time water-bindingagents and which are generally suitable are sulfuric acid, sulfuric acidmonohydrate and It is preferred to use at least to sul 1 oleum.

Patented June 20, 1 961 tetrachlorisophthalaldehyde; and also theomega-halogenated xylenes, as for example omega, omega,omega',omega'tetrachlor para-xylene, omega,omegapmegapmega tetrabrom para xylene, 2,5omega,omega,omega,omega' hexachlor paraxylene, 2,5omega,omega,omega',omega"- hexabrompara xylene, 2,3,5,6 omega,omega,omega',omega- I 2,4 omega,omega, omega',-

1,4 bistrichlor- 2. methylbenzene, 4,6 dichlor 1,3 bis trichlormethyl-'z omega,omega,omega,omega',omega'a furic acid. Especially good resultsare obtained by working in 99% sulfuric acid. When oleum is used it ispreferred to use up to 10% oleum.

The condensation can also be carried out in inert organic solventsand/or diluents, such as nitrobenzene, trichlorobenzene or naphthalene,especially when starting for example from acid chlorides, aldehydes oromegahalogenxylenes. Suitable temperatures for reaction in sulfuric acidand/ or sulfuric acid mouohydrate are in general 100 to 160 C., and forreaction in organic solvents temperatures of about 150 to 220 C. aresuitable. In many cases the reaction takes place immediately during theheating of the reaction mixture up to the said temperatures and is endedwhen these temperatures have been reached. In other cases the reactionmixture must be kept at these higher temperatures for up to 8 hours ifit is desired to achieve a complete condensation of the reactants. Thenew process is of special technical interest when starting fromomegahalogenxylenes and using sulfuric acid or nitrobenzene as solvent.

The dyestuffs according to this invention are characterized, in contrastto the imidazole dyestuffs of the anthraquinone series hitherto known,by a high color strength and they have especially good wet fastnessproperties. The new imidazole dyestuffs of the anthraquinone series arevaluable yellow vat dyestuffs for dyeing and/ or printing variousstructures, such as fibers, threads, flocks, foils, woven or knittedfabrics of native and/or regenerated cellulose. They are also suitablefor dyeing synthetic materials, especially linear polyamides.

The following examples will further illustrate this invention but theinvention is not restricted to these examples. The parts and percentagesare by weight.

Example 1 3.5 parts of terephthalic acid are added to a solution of 10parts of LZ-diaminoanthraquinone in 100 parts of concentrated sulfuricacid, and the mixture is heated to 150 to 160 C. and kept at thistemperature for 8 hours. After cooling, the reaction mixture is pouredinto ice-water and the deposited precipitate is filtered off by suction,washed until free from acid and dried.

If desired, the dyestuff may also be separated by adjusting the sulfuricacid solution of the dyestuff, by the careful addition of water, to theacid concentration at which the dyestult' separates as the sulfate. Bydecomposing the sulfate with water, the new dyestufi is obtained in pureform. This kind of separation of a dyestuff from the reaction mixture istermed fractionation in the following examples.

The yellow dyestuff obtained in a very good yield has good solubility inconcentrated sulfuric acid; but in organic solvents, it is less solublewith a yellow color or is insoluble. The dyestuff dyes cotton yellowshades from a violet-red vat and has the following formula:

tax CW0? for 1 to 3 hours. After cooling, the reaction mixture is pouredinto ice-water or the dyestu'fiF is fractionated as described inExample 1. The yellow dyestuff obtained in very good yields is solublewith a yellow color in concentrated sulfuric acid. It is insoluble inorganic solvents or dissolves only slightly with a yellow color. Thedyestutf dyes cotton yellow shades from an orange-red vat and has thefollowing formula:

H C -C H O N N 0 n 1 u N W 1 0 0 Example 3 The dyeing on cotton isyellow.

Example 4 6.8 parts of 2,5-dibromoterephthalic acid are introduced intoa solution of 10 parts of l,2 diaminoanthraquinone in parts of sulfuricacid monohydrate, and the mixture heated to to C. and kept at thistemperature for 3 hours. After cooling, the reaction mixture is pouredinto ice-water or the dyestuif fractionated as described in Example 1.The yellow dyestutf obtained in good yields is soluble in sulfuric acidwith a yellow color and is insoluble or only slightly soluble in organicsolvents. It dyes cotton yellow shades from a violet vat and has thefollowing formula:

0 N \N/ O H l Br I II II It 0 0 (VI) Example 5 5 parts of4,6-dichlorisophthalic acid are added to a solution of 10 parts of1,2-diaminoanthraquinone in 100 parts of sulfuric acid monohydrate, andthe mixture heated to 150 to 160 C. and kept at this temperature for 3hours. After cooling, the reaction mixture is poured into ice-water orthe dyestufi fractionated in the asse't-sss 1 way described inExample 1. The yellow dyestuff obtained in a very good yield is solublein sulfuric acid with a yellow color and is insoluble or only slightlysoluble in organic solvents. It yields a red vat. The dyeing on cottonis yellow. The dyestulf has the following formula:

H C C H O \N/ \N/ 0 1! I I ll j -N N o 0 (VII) Example 6 parts of1,2-diaminoanthraquinone are dissolved in 150 parts of nitrobenzenewhile heating. Into the solution there are introduced 0.1 part ofpyridine and then at 120 C. 4.3 parts of terephtaloyl chloride in smallportions. The solution is then heated during the course of 1 to 2 hoursat 180 C., kept at this temperature for 1 hour, further heated to 200C., the temperature kept at 200 C. for 1 hour, and then cooled to 120 C.At this temperature, the reaction product is filtered oil by suction,washed with nitrobenzene at 120 C., and then washed free fromnitrobenzene with methanol and dried. The dyestutf obtained in a verygood yield is identical with the dyestull prepared according to Example1.

Example 7 The terephthaloy-l chloride in Example 6 is replaced by thesame amount of isophthaloy-l chloride. A dyestuff is obtained in a verygood yield which is identical with the dyestufl obtainable according toExample 2.

Example 8 The procedure of Example 6 is followed but starting from 5.8parts of 2,S-dichlorterephthaloyl chloride instead of from 4.3 parts ofterephthaloyl chloride.' A yellow dyestuff is obtained in .a good yieldwhich is identical with the dyestuff prepared according to Example 3.

Example 9 10 parts of 1,Z-diaminoanthraquinone are dissolved in 200par-ts of nitrobenzene while heating. Into the solution there are thenintroduced 0.1 part of pyridine and then at 120 C. 7.6 parts of2,5-dibromoterephthaloyl chloride in small portions. The whole is thenheated within 1 to 2 hours to 180 C., the temperature kept at 180 C. for1 hour, further heated to 200 C., the temperature held at 200 C. for 1hour and then cooled to 120 C. The reaction product is filtered oil bysuction at 120 C., washed with hot nitrobenzene at the same temperature,and then washed free of nitrobenzene with methanol and dried. Thedyestuif obtained in a very good yield is identical with the dyestutfprepared according to Example 4.

Example 10 10 parts of 1,2-diaminoanthraquinone are dissolved in T 150parts of nitrobenzene by heating. 0.1 part of pyridine is added to thesolution and then 5.8 parts of 4,6- dichlorisophthaloyl chloride areintroduced at 120 C. in small portions. The solution is then heatedduring 1 to 2 hours to 180 C., the temperature held for 2 hours at 180C. and then cooled to 120 C. At this last temperature, the reactionproduct is filtered oil by suction, washed with nitrobenzene at 120 C.,and then washed free of nitrobenzene with methanol and dried Thedyestuflf obtained in a good yield is identical with the" dyestutfprepared according to Example 5.

6 Example 11 10 parts of 1,2-diaminoanthraquinone are dissolved in 200parts of nitrobenzene while heating. Into the ,solution there are thenintroduced 0.1 part of pyridine, and

sulfuric acid; it is insoluble in organic solvents or only The dyestuffdyes slightly soluble with a yellow color. cotton yellow shades from aviolet vat and has the following formula:

O.CHs

Example 12 (VIII) 10 parts of 1,2-diaminoant-hraquinone are dissolved inparts of nitrobenzene while heating. At about 100 C. 2.9 parts ofterephthalaldehyde are added in small portions and the solution isheated within 1 to 2 hours to 180 C. and kept at this temperature for anhour. After cooling to C., the reaction product is filtered off bysuction, and washed with hot nitrobenzene at 120 C. The dyestufi is thenwashed free of nitrobenzene with methanol and dried. The dyestuifobtained in a very good yield is identical with the dyestuff preparedaccording to Example 1 or 6.

Example 13 10 parts of 1,2-diaminoanthraquinone are dissolved in partsof nitrobenzene while heating. At about 100 C., 4.3 parts of2,5dichlorterephtalaldehyde are added in small portions, the solutionheated within 1 to 2 hours to C. and kept at this temperature for anhour. After coo-ling to 120 C., the reaction product is filtered off bysuction, washed with hot nitrobenzene at 120 C., washed free ofnitrobenzene with methanol and dried. The dyestuff obtained in a verygood yield is identical with the dyestuff prepared according to Example3 or 8.

Example 14 The procedure of Example 13 is followed but 200 parts ofnitrobenzene are used instead of 15 0 parts of nitrobenzene and 6.2parts of 2,5-dibromterephthalaldehyde are used instead of 4.3 parts of2,5dichlorterephth-alaldehyde. There is obtained in a good yield thesame dyestuff as can be obtained according to Example 4 or 9.

Example 15 10 parts of 1,2-diaminoanthraquinone are dissolved in 150parts of nitrobenzene while heating. At about 150 C. there is introducedinto the solution in small portions 6.6 parts of2,5-omega,omega,omegaf,omega',-hexachlorpara-xylene, the whole heated inthe course of an hour to 180 C., the temperature held for an hour at 180C., heated to 200 C., the temperature held for an hour at 200 C. and themixture cooled to 120 C. At this temperature the reaction product isfiltered oil by suc- 7 tion, washedfirst with hot nitrobenzene at 120C., then with methanol until free of nitrobenzene and dried. A dyestutfis obtained in a very good yield which is identical with the dyestuffprepared according to Example 3, 8 or 13.

By replacing the 6.6 parts of 2,5-omega,omega,omegaomega-hexachlor-para-xylene by 12.5 parts of2,5-dichlor-omega,omega,omega,omega-tetrabrom-para-xylene, the samedyestutf is obtained in a very good yield.

Example 16 The 2,5-omega,omega,omega,omega'-hexachlor-paraxylene inExample is replaced by 12.2 parts of 2,5-omega,omega,omega,omega-hexabrom-para-xylene. A dyestuff is obtained ina very good yield which is identical with the dyestuif preparedaccording to Example 4, 9 or 14.

Example 17 8.9 parts of omegapmega,omega,omega-tetrabrommeta-xylene areadded to a solution of 10 parts of 1,2- diamino-anthraquinone in 100parts of sulfuric acid monohydrate, the mixture heated to 125 to 130 C.and kept for 2 hours at this temperature. After cooling, the reactionmixture is poured into ice-water or the dyestuff fractionated asdescribed in Example 1. The dyestuff obtained in a very good yield isidentical with the dyestutf prepared according to Example 2 or 7.

Example 18 6.6 parts of2,5-omega,-omega,omega',omega'-hexachlor-para-xylcne are introduced intoa solution of 10 parts of 1,Z-diamino-anthraquinone in 100 parts ofsulfuric acid monohydrate, the mixture heated to 100 C. and kept at thistemperature for 2 hours. After cooling, the reaction mixture is pouredinto ice-water or the dyestuif is fractionated as described inExample 1. A dyestutf is obtained in a very good yield which isidentical with the dyestuif prepared according to Example 3, 8, 13 or15.

By replacing the 1,2-diaminoanthraquinone with the same weight of1,2-diamino-3-methoxyanthraquinone and using 5.9 parts of2,5-omega,omega,omega',omega-hexachlor-para-xylene, a yellow dyestutf isobtained in a very good yield which is soluble in sulfuric acid with ayellow color. The new dyestutf dyes cotton yellow shades from ablue-violet vat and has the following formula:

N I\l O.CH3 HaC.O

a H O N I \N/ 0 II 1 Cl H I N N- A Example 19 By following the procedureof Example 18 but starting from 10 parts of 1,2diamino-3-bromanthraquinone in- .stead of 1,2-diaminoanthraquinone and4.8 parts of 2,5-

omega,omegapmega',omega-hexachlor-para xylene instead of 6.6 parts, ayellow dyestuff is obtained in a very good yield which dissolves Well inconcentrated sulfuric acid. The new dyestuff is insoluble in organicsolvents or .only slightly soluble with a yellow color and dyes cottonyellow shades from a violet vat. The dyestuff has the following formula:

0 ll i) i 0 Example 20 Example. 21

3.5 parts of terephthalic acid are introduced into a solution of 5 partsof 1,2-diaminoanthraquinone in parts of sulfuric acid monohydrate, themixture heated for 1 to 3 hours at C., 6.7 parts of 1,2-diamino-3-bromanthraquinone introduced and kept for a further 1 to 3 hours at150 C. After cooling, the reaction mixture is poured into ice-water orthe dyestulf fractionated as described in Example 1. The yellow dyestuffobtained in a very good yield is soluble in concentrated sulfuric acidwith a yellow color. The dyestuff dyes cotton yellow shades from a redvat and has the following formula:

sis

O O (XIII) 9 We claim: 1. A dyestufi of the formula:

/C A o\ N N o N N E 1 ID DI Q E E 0 (II) in which each of D, D, E and Erepresents a nonvalent substituent selected from the class consisting ofhydrogen chlorine, bromine and lower alkoxy, and wherein A represents adivalent radical selected from the class consisting of unsubstitutedmetaand para-phenylene and metaand para-phenylene containing up to twomonovalent substituents selected from the class consisting chlorine andbromine.

2. The dyestufi of the formula:

3. The dyestufi of the formula:

4. The dyestufl of the formula:

10 5. The dyestufi of the formula:

H C C O N N O l l O.CHa 1130.0

6. The dyestufi of the formula:

H 0- -o H 0 I l I 7. The dyestutf of the formula:

References Cited in the file of this patent UNITED STATES PATENTS1,022,781 Friedmann Apr. 9, 1912 FOREIGN PATENTS 251,480 Germany Oct. 8,1912 591,980 Great Britain Sept. 3, 1947 OTHER REFERENCES Beilstein(Handbuch, 4th Ed.), vol. 27, 2nd Sup., p.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No,2,989,535 June 20, 19 1 Hermann Geere n et a1.

It is hereby certified that error appearsin the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 10 lines 7 to 12, the right-hand portion oi the formula shouldappear as shown below instead oi as in the patent:

Signed and sealed this 2nd day of January 1962.

(SEAL) Attest:

ERNEST w. SWIDER DAVID L- LADD Attesting Officer Commissioner of Patents

1. A DYESTUFF OF THE FORMULA: